ICS Advisory

Siemens Teamcenter Active Workspace

Last Revised
Alert Code
ICSA-21-350-18

1. EXECUTIVE SUMMARY

  • CVSS v3 6.8
  • ATTENTION: Exploitable remotely/low attack complexity
  • Vendor: Siemens
  • Equipment: Teamcenter Active Workspace
  • Vulnerability: Path Traversal

2. RISK EVALUATION

Successful exploitation of this vulnerability could allow an attacker to achieve remove code execution.

3. TECHNICAL DETAILS

3.1 AFFECTED PRODUCTS

The following versions of Teamcenter Active Workspace, a collaboration tool, are affected:

  • Teamcenter Active Workspace v4.3: All versions prior to v4.3.11
  • Teamcenter Active Workspace v5.0: All versions prior to v5.0.10
  • Teamcenter Active Workspace v5.1: All versions prior to v5.1.6
  • Teamcenter Active Workspace v5.2: All versions prior to v5.2.3

3.2 VULNERABILITY OVERVIEW

3.2.1    IMPROPER LIMITATION OF A PATHNAME TO A RESTRICTED DIRECTORY ('PATH TRAVERSAL') CWE-22

The application contains an unsafe unzipping pattern that could lead to a zip path traversal attack. This could allow an attacker to execute a remote shell with admin rights.

CVE-2021-41547 has been assigned to this vulnerability. A CVSS v3 base score of 6.8 has been calculated; the CVSS vector string is (AV:N/AC:L/PR:H/UI:R/S:U/C:H/I:H/A:H).

3.3 BACKGROUND

  • CRITICAL INFRASTRUCTURE SECTORS: Multiple Sectors
  • COUNTRIES/AREAS DEPLOYED: Worldwide
  • COMPANY HEADQUARTERS LOCATION: Germany

3.4 RESEARCHER

Siemens reported this vulnerability to CISA.

4. MITIGATIONS

Siemens recommends updating to the latest version of the software:

Siemens has identified the following specific workarounds and mitigations users can apply to reduce the risk:

  • Harden the application host to prevent local access by untrusted personnel

As a general security measure, Siemens strongly recommends protecting network access to devices with appropriate mechanisms. In order to operate the devices in a protected IT environment, Siemens recommends configuring the environment according to the Siemens operational guidelines for industrial security and following the recommendations in the product manuals.

For additional information, please refer to Siemens Security Advisory SSA-133772

CISA recommends users take defensive measures to minimize the risk of exploitation of this vulnerability. Specifically, users should:

  • Minimize network exposure for all control system devices and/or systems, and ensure they are not accessible from the Internet.
  • Locate control system networks and remote devices behind firewalls and isolate them from the business network.
  • When remote access is required, use secure methods, such as Virtual Private Networks (VPNs), recognizing VPNs may have vulnerabilities and should be updated to the most current version available. Also recognize VPN is only as secure as its connected devices.

CISA reminds organizations to perform proper impact analysis and risk assessment prior to deploying defensive measures.



CISA also provides a section for control systems security recommended practices on the ICS webpage on cisa.gov. Several recommended practices are available for reading and download, including Improving Industrial Control Systems Cybersecurity with Defense-in-Depth Strategies.

Additional mitigation guidance and recommended practices are publicly available on the ICS webpage on cisa.gov in the Technical Information Paper, ICS-TIP-12-146-01B--Targeted Cyber Intrusion Detection and Mitigation Strategies.



Organizations observing any suspected malicious activity should follow their established internal procedures and report their findings to CISA for tracking and correlation against other incidents.

No known public exploits specifically target this vulnerability.

This product is provided subject to this Notification and this Privacy & Use policy.

Vendor

Siemens